Find the estimated sum of 4,380 and 18,765 to the nearest thousand
The Correct Answer and Explanation is:
Estimated Sum of 4,380 and 18,765 to the Nearest Thousand
Correct Answer: 23,000
Explanation
When estimating the sum of numbers to the nearest thousand, we simplify the calculation by rounding each number to the nearest thousand before adding them. This method is especially useful when we want a quick approximation rather than an exact answer.
Let’s go through this step by step:
Step 1: Round Each Number to the Nearest Thousand
- 4,380:
To round to the nearest thousand, we look at the hundreds digit.
In 4,380, the hundreds digit is 3 (since it’s 380).
Because 3 is less than 5, we round down.
So, 4,380 rounds to 4,000. - 18,765:
The hundreds digit here is 7 (since it’s 765).
Since 7 is 5 or more, we round up.
So, 18,765 rounds to 19,000.
Step 2: Add the Rounded Numbers
Now we add the rounded numbers:
- 4,000 + 19,000 = 23,000
Why Estimation Is Useful
Estimation is a powerful tool in everyday math. It helps when we want to make quick decisions or check whether an exact answer seems reasonable. In this case, while the exact sum of 4,380 and 18,765 is 23,145, the estimated sum of 23,000 is close and easy to compute mentally.
Using rounding also helps avoid small arithmetic errors, especially when dealing with large numbers or doing calculations without a calculator.
In real life, such approximations are helpful in budgeting, shopping, or estimating distances and times—any situation where you don’t need perfect precision but need a good idea of the total.
Final Estimated Sum: 23,000
